This is an aggravating feature, at least to me. For example, I was able to answer this question in one line, providing more than enough information. It was auto-converted to a comment (which does not accept markdown formatting so it was misstyled). For some questions, responding with "no" is a completely valid, correct, and informative answer. Now I have to pad my answers with unnecessary text to get around the convert-to-comment nonsense.

You may think you are double awesome for taking only one line for your answer (including the code!).

But you aren't. You should either have posted a comment detailing the possible duplicate, flagged for mod attention (because you don't have enough rep to cast a close vote), or....

... you could have quoted a relevant part from the target you linked to, as a way of explaining your answer. A terse bit of code followed by a link is not an answer with any value. If you have a link to a suitable answer but can't provide any more context then just leave the link as a comment.